This project 1. evaluates the angiogenic and cellular proliferative properties of epidermal growth (EGF) and fibroblast growth factor (FGF) placed in high concentration in different parts of the eye, 2. determines aging changes in Bruch's membrane that, in the presence of angiogenic factors, could predispose to subretinal neovascularization. We hypothesize that naturally occurring growth factors such as EGF or FGF are responsible for diseases with vascular or cellular proliferation, for example: proliferative diabetic retinopathy, proliferative sickle retinopathy, senile macular degeneration, surface wrinkling retinopathy, and massive vitreous retraction. The experiments are designed to stimulate vascular and cellular proliferation with EGF or FGF to reproduce in the animal model the vascular and cellular proliferative diseases. Each growth factor is put in Elvax, from which it leaches for weeks. The reponse of retinal glia, retinal vessels, retinal pigment epithelium, and choriocapillaries to EGF and FGF will be tested. The material in Elvax pellets will be placed in cornea, anterior chamber, vitreous, or choroid. Eyes without posterior ocular injury or eyes with injuries to Bruch's membrane or the internal limiting lamina will be used. Observation for neovascularization or cellular proliferation will be by ophthalmoscopy, fundus photography, fluorescein angiography, light microscopy, tritiated thymidine autoradiography, and correlated scanning and transmission electron microscopy. Human cadaver specimens will be examined to determine topographic features of aging Bruch's membrane.